Problem: Khan.scratchpad.disable(); Daniel sells magazine subscriptions and earns $$9$ for every new subscriber he signs up. Daniel also earns a $$28$ weekly bonus regardless of how many magazine subscriptions he sells. If Daniel wants to earn at least $$90$ this week, what is the minimum number of subscriptions he needs to sell?
Answer: To solve this, let's set up an expression to show how much money Daniel will make. Amount earned this week $=$ $ $ Subscriptions sold $\times$ Price per subscription $+$ Weekly bonus Since Daniel wants to make at least $$90$ this week, we can turn this into an inequality. Amount earned this week $\geq $90$ Subscriptions sold $\times$ Price per subscription $+$ Weekly bonus $\geq $90$ We are solving for the number of subscriptions sold, so let subscriptions sold be represented by the variable $x$ We can now plug in: $x \cdot $9 + $28 \geq $90$ $ x \cdot $9 \geq $90 - $28 $ $ x \cdot $9 \geq $62 $ $x \geq \dfrac{62}{9} \approx 6.89$ Since Daniel cannot sell parts of subscriptions, we round $6.89$ up to $7$ Daniel must sell at least 7 subscriptions this week.